package sms

import (
	"fmt"

	openapi "github.com/alibabacloud-go/darabonba-openapi/v2/client"
	dysmsapi "github.com/alibabacloud-go/dysmsapi-20170525/v4/client"
	"github.com/alibabacloud-go/tea/tea"

	"gotest/internal/config"
)

// AliyunSender 阿里云短信发送器
type AliyunSender struct {
	accessKeyID     string
	accessKeySecret string
	signName        string
	templateCode    string
	client          *dysmsapi.Client
}

// NewAliyunSender 根据阿里云短信配置创建发送器实例
func NewAliyunSender(cfg *config.AliyunSMS) *AliyunSender {
	return &AliyunSender{
		accessKeyID:     cfg.AccessKeyID,
		accessKeySecret: cfg.AccessKeySecret,
		signName:        cfg.SignName,
		templateCode:    cfg.TemplateCode,
	}
}

// Send 通过阿里云短信服务发送验证码
func (s *AliyunSender) Send(phone string, code string) error {
	// 关键配置校验，AccessKeyID/AccessKeySecret 为空时直接返回错误
	if s.accessKeyID == "" || s.accessKeySecret == "" {
		return fmt.Errorf("阿里云短信未配置: AccessKeyID/AccessKeySecret 不能为空")
	}

	// 懒加载客户端，避免构造时因配置缺失直接 panic
	if s.client == nil {
		openapiCfg := &openapi.Config{
			AccessKeyId:     tea.String(s.accessKeyID),
			AccessKeySecret: tea.String(s.accessKeySecret),
			Endpoint:        tea.String("dysmsapi.aliyuncs.com"),
		}
		client, err := dysmsapi.NewClient(openapiCfg)
		if err != nil {
			return fmt.Errorf("创建阿里云短信客户端失败: %w", err)
		}
		s.client = client
	}

	// 构造发送请求，TemplateParam 为 JSON 格式的模板参数
	req := &dysmsapi.SendSmsRequest{
		PhoneNumbers:  tea.String(phone),
		SignName:      tea.String(s.signName),
		TemplateCode:  tea.String(s.templateCode),
		TemplateParam: tea.String(fmt.Sprintf(`{"code":"%s"}`, code)),
	}

	// 调用阿里云短信接口发送
	resp, err := s.client.SendSms(req)
	if err != nil {
		return fmt.Errorf("阿里云短信发送失败: %w", err)
	}

	// 校验业务返回码，Code 为 "OK" 表示发送成功
	if resp.Body == nil || resp.Body.Code == nil || *resp.Body.Code != "OK" {
		errMsg := "未知错误"
		if resp.Body != nil && resp.Body.Message != nil {
			errMsg = *resp.Body.Message
		}
		return fmt.Errorf("阿里云短信发送失败: %s", errMsg)
	}

	return nil
}